A method of the type mentioned in the preamble is described by G. Kowalski and W. Wagner in "OPTICA ACTA", 1977, Vol. 24, no. 4, pages 327-384. According to this method an X-ray source, whose radiation is collimated to a flat fan-shaped radiation beam which is incident on an array of adjacent detectors disposed in said plane is rotated about a centre of rotation together with said detector array, which supplies the measuring data which are a measure of the attenuation along individual radiation paths in such a way that the radiation beam irradiates the body slice to be examined in different directions. The size (width) of the measuring area of the individual detectors divides the radiation beam into separate subbeams, which in their turn define the shape and size of the radiation paths.
The absorption distribution of the irradiated body section can then be reconstructed as an image in known manner from the measuring data thus obtained.
However, the centre of rotation of the examination apparatus (radiation source detector array) should then be known exactly. If this centre is not known with sufficient accuracy, blurring in the reconstructed computerized tomography image results. Moreover, if the examination apparatus is not rotated through a full revolution lack of knowledge of the centre of rotation can also gives rise to streaking artefacts.